Optical characteristics of microalgae culture in installation with external light sensors

by

R.P. Trenkenshu, A.S. Gulin

1The A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS,

 RF, Sevastopol, Nakhimov Av., 2

DOI: 10.33075/2220-5861-2024-3-65-70

UDC [579:582.26/.27]:581.143:535.34/.35                

EDN: https://elibrary.ru/lhlupv

Abstract:

The paper formulates the main problems that arise when determining the biomass of a microalgae culture using flow-through optical sensors, namely the need to immerse them in the culture, ensure circulation of the cultural suspension through the sensor, and combat fouling of the internal surfaces of the sensor. Taking into account the above shortcomings, a new system for determining biomass using external optical sensors is proposed, which makes it possible to assess the culture density, pigment composition and light conditions in which cells are grown in cultivation systems. External optical sensors do not require immersion in the culture, nor do they require continuous circulation of the culture medium. Based on the performed mathematical modeling and readings of external sensors on the input illuminated surface and at the output of the plane-parallel installation, equations are obtained that make it possible to calculate the pigment concentration in the microalgae culture. It is found that the absorption coefficient values ​​obtained during experimental measurements deviate from the Bouguer-Lambert-Baer law. This deviation is most pronounced in the region of high pigment concentrations and the corresponding culture density. For the most accurate description of experimental data over the entire range of culture densities, a semi-empirical equation is proposed.

Keywords: optical method of biomass control, pigment composition, chlorophyll, external light sensors.

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REFERENCES

  1. Chekushkin А.А., Gulin A.S., and Lelekov A.S. Sistema kontrolya rosta kul’tury Arthrospira platensis v polupromyshlennykh usloviyakh (System for controlling the growth of Arthrospira platensis culture in semi-industrial conditions). Nanotechnology: development, application – XXI century, 2024, Vol. 16, No. 2, pp. 23–30.
  2. Nichiporovich A.A. Rabocheye soveshchaniye po voprosam izmereniya opticheskogo izlucheniya dlya tseley agro-meteorologii, fiziologii i ekologii rasteniy (Workshop on measuring optical radiation for the purposes of agro-meteorology, physiology and ecology of plants). Plant Physiology, 1969, Vol. 7(6), pp. 332–350.
  3. Trenkenshu R.P., Borovkov A.B., and Lelekov A.S. Ustanovka dlya kul’tivirovaniya nizshikh fototrofov (Installation for cultivation of lower phototrophs). Patent No. 150345, RF, МПК C12N 1/12. 2015.
  4. Falkowski P. and Kiefer A. Chlorophyll a fluorescence in phytoplankton: relationship to photosynthesis and biomass. Journal of Plankton Research, 1985, Vol. 7, pp. 715–731.
  5. Behrenfeld M.J., Boss E., Siegel D.A., and SheaD.M. Carbon-based ocean productivity and phytoplankton physiology from space. Global Biogeochem. Cycles, 2005, Vol. 19, GB1006. doi:10.1029/2004GB002299
  6. Gulin A.S., Trenkenshu R.P., and Chernyshev D.N. Dekompozitsiya krasnoy oblasti spektra pogloshcheniya – nachal’nyy metod otsenki pigmentnogo sostava mikrovodorosley (Decomposition of the red region of the absorption spectrum is an initial method for assessing the pigment composition of microalgae). Current issues in biological physics and chemistry, 2020, Vol. 5, No. 2, pp. 239–245.
  7. Lelekov A.S. and Trenkenshu R.P. Fundamental’nyye printsipy modelirovaniya fotobiosinteza mikrovodorosley (Fundamental principles of modeling photobiosynthesis of microalgae). Questions of modern algology, 2018, No. 3 (18), pp. 1–7.
  8. Trenkenshu R.P., Lelekov A.S., and Novikova T.M. Lineynyy rost morskikh mikrovodorosley v kul’ture (Linear growth of marine microalgae in culture). Marine Biological Journal, 2018, Vol. 3, No. 1, pp. 53–60.

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